This invention relates to a dry etching apparatus, and more particularly to a dry etching apparatus suitably used for the anisotropic dry etching of a material and rarely causing a side etched portion to occur in the material.
Efficiently practicing the highly-accurate etching of a semiconductor substrate and various kinds of insulating films or various kinds of conductive films and semiconductor films constitute techniques essential to the manufacturing of VLSI, and various kinds of new techniques concerning anisotropic etching rarely causing undercuts to occur in an object material have been developed and studied. Regarding, especially, a method of or an apparatus for cooling an article to be etched on a wafer table, the techniques proposed by, for example, Japanese Patent Laid-Open No. 158627/1985 constitute examples of the conventional techniques of this kind.
According to the above conventional techniques, an article to be etched is cooled to a temperature of not higher than minus several tens of degrees centigrade by using a heat pipe as a cooling means, so as to prevent the occurrence of the side etching of the article. However, the range of controllable temperatures is narrow. In order to carry out an etching operation at a low temperature without trouble, it is, of course, necessary that an optimum temperature be selected in accordance with the purpose of the etching and the kind of an article to be etched. If the range of controllable temperatures is narrow, an optimum temperature cannot be selected, and it is difficult to carry out an etching operation excellently.